Windows Update And McAfee Doesn't Open At Start Up

The other day my compter was working just fine, until the battery died and it shut off. Ever since then, when I start it up McAfee doesn't open at start up, or at all for that matter. And, everytime I double click on the shortcut, the picture comes up, but it just stays that way, and then the desktop freezes. And, when I try to open something that needs permission to continue, like when I right click and select "Run as administrator, nothing happens. Also, when I try to uninstall something, nothing happens. The internet icon on the taskbar is always frozen, indicating that there's no connection, when there actually is.

Most programs do the same as McAfee, althought Internet Explorer 8 works, but not well. It stops working alot and hulu videos don't work for instance. Also, anytime I try to download something on IE8, it quickly jumps to 99% and stops there. And, whenever I try system restore in help, the window stops responding. My mom thinks that it might be a virus from a song that she downloaded on LimeWire 5.1.1 PRO. But again, McAfee won't work. And my registry cleaning software won't open, because it has to ask permission. Which doesn't work. Windows Update doesn't even respond when I open it. What should I do?